Hi, SLD. You are getting the right info but here's a couple of things to consider. For priming drywall, I prefer Zinnser's B-I-N. It is a shellac based product and seals the surface nicely. It also seals in any dirt or stains so you would not have to wash with TSP. Washing would be troublesome to me unless you used the absolute minimum of water. Easier just to use a primer that also takes care of that problem. B-I-N is alcohol based so be sure you have good ventillation.